Notes

Acknowledgments

We are grateful to Drs. Tong-Seung Tseng, Tzung-Meng Wu, and Kuo-Chen Yeh for comments and suggestions on the manuscript; and Dr. Yee-Yung Charng for technical assistance with thermal imaging. We thank the electron microscopy laboratory of Tzu Chi University. We also thank ABRC and TRIM for providing seeds. This work was supported by the National Science Council, Taiwan, ROC (NSC96-2317-B-008-003 and NSC98-2324-B-008-002 to C.H. Yeh).